1. Field of the Invention
This invention pertains to an inter-processor communications control system, and more specifically to an inter-processor communications control system between a call processor and a processor of a communications control device for controlling ATM communications e.g. for use in an ATM switch.
2. Description of the Related Arts
Ever since the CCITT (Consultative Committee on International Telephone & Telegram) endorses an asynchronous transfer mode (ATM) switch system as a standard exchange system of the next generation, its researches have actively conducted especially on the technology for realizing a broadband ISDN (Integrated Services Digital Network).
Such an ATM switch system often has many devices capable of realizing various functions located large distances away. It is necessary to efficiently realize communications among the processors of respective devices, for improving the quality and reliability in processing a fault and in connecting paths throughout an ATM switch system.
Such an ATM switch system was initially implemented as on a system having direct bus connections among processors e.g. between a call processor and a processor of a communications control device for controlling communications in the systems. In such a case, an inter-processor communications control is rather simple, which can be realized chiefly by the functions of a call processor.
However, when the distance between the call processor and the communications control device is large and a cable connects two processors, since a communications speed becomes slow and communications capacities are limited in such communications, it is required of more efficiently transmitting data between the call processor and the communications control device.